Electric discharge lamp luminaire



y 1957 A. A. BRAINERD 2,793,285

ELECTRIC DISCHARGE LAMP LUMINAIRE I Filed 001:. 26, 1955 3 Sheets-Sheet l m F 63 33 T ig H J Z6-"/"--? 313 I 1.; I I I 46%?!" 1 E E I I I I i I 1 i I I 5: 1 i 8 B8 1 i Ar mar/1. Braifierd,

ATTORNEYS.

May 21, 1957 A. A. BRAINERD ELECTRIC DISCHARGE LAMP LUMINAIRE s Sheets-Sheet 5 Filed Oct. 26. 1953 INVENTOR. I Ari/7 111' A. Braiherd,

ATTORNEYS.

United States Patent ELECTRIC DISCHARGE LAMP LUMINAIRE- Arthur A. Brainerd, Erwinna, Pa.

Application October 26, 1953, Serial No. 388,102 6 Claims. (Cl. 240-25) This invention relates to a luminaire, and more specifically concerns a luminaire of the electric discharge type which is particularly advantageous-for lighting streets, highways and the like.

It is well known that the efliciency of electric discharge lamps is considerably higher under. optimum temperature conditions than the efficiency of incandescent lamps of the same wattage. Electric discharge lampshave, therefore, gone into extensive use in factories, office buildings and the like.

in my prior U. S. Patent No. 2,610,289, granted September 9, 1952, I disclose and claim an;electric-. discharge lamp luminaire which has capacity for efficient operation at various temperatures falling generally within the .range of natural ambient temperature conditions. Like the luminaire of the aforementioned issued patent, the luminaire constructed in accordance with this invention is enclosed and is electrically heated, and has capacity 'for eflicient operation under natural ambient conditions.

It is an object of this invention to provide an-electric discharge lamp luminaire which is adapted to be mounted adjacent to a street or highway'to direct a Hood of illumination at an angle across the highway and at an elevation slightly above but immediately adjacent to the highway level.

Still another object of this inventionis to create an electric discharge lamp luminaire of an improved, nonglare design.

Still another object is to create a luminaire'having a plurality of enclosed light sources together with reflector means which is adapted to focus and direct the light'atan acute angle across a street, highway or the like;

Still another object of this invention is to create a luminaire of simple and practical construction which has an improved lighting efliciency as compared to other luminaires and is sufliciently rugged for permanent installation adjacent a street, highway or the like.

Other objects and advantages of this invention, including the simplicity and economy'of the same, will further appear hereinafter and in the drawings, whereof:

Fig. 1 represents a plan view of a divided highway, showing a plurality of electric discharge lamp luminaires positioned adjacent thereto;

Fig. 2 represents a side. elevation of an electric discharge lamp luminaire constituting'one specific embodiment of this invention;

Fig. 3 represents a plan view of the luminairetaken as indicated by the lines and arrows III-III which appear in Fig. 2, with certain parts broken away in-order to illustrate further important details;

Fig. 4 represents a vertical sectional view taken. as indicated by the lines and arrows IV-IV which appear in Fig. 3, the central portion of the luminaire beingv broken away;

Figs. 5 and 6 represent sectional views'taken as indicated by the lines and arrows V-V and VI-VI respectively, which appearin Fig. 4;

2,793,285 P atente d May 21, 1957 2' I means for one of the-reflector members, taken as indicated by the lines and arrows VH' -VII which appear in Fig. 5; and

Fig. 8 representsa view in perspective of the electric discharge lamp luminaire shown in the preceding figures.

Turning now to the specific embodiment of the invention selected for illustration in the drawings, Fig. 1 shows a divided highway having a .pair of spaced apart highway strips 10, 11 witha central strip 12 therebetween. Located at uniformly spaced positionsalong the central strip 12, along two parallellines extending. adjacentto the respective strips 10, 11, are a plurality of electric discharge lamp luminaires; 13. The luminaires 13 are enclosed and have reflectors 14which are constructed and arranged to direct light rays across the highway strips 10, 11 at an acute angle with respect to the edge of the highway. The relatively heavy lines (a) in Fig. 1 illustrate the fact that the majority of the light from the luminaires 13 is directed along..a more or less definite zone, while the relatively light lines (b) in Fig. 1 represent light beams of relatively minor intensity which border'the majorzone. From Fig. 1 it will be appreciated'that the-'majority 'of the lightfrom the luminaires 13. is directed generally in the direction of travel of the vehicles on the highway which is indicated by the arrows (c), and'at an acute angle with respect thereto. Accordingly, the vehiclesonthe'highways are flooded with bright Fig. 7 represents a sectional viewshowing the mounting 9 light without creating any" noticeable glare in the eyes of the drivers, either directly orv by reflection from the rear View mirrors, the highway being incidentally illuminated by spill light. The luminaire is supported at such an angle that the bottom of the light beam passes across the highway above and substantially parallel to its surface. The light, whichis thus directed horizontally close to the highway surface, gives maximum visibility in. fog or other adverse weather conditions. This is an important and advantageous feature of this invention.

Turningnow toFig; 2 of the drawings, the construction of the luminaires'is brought out in more particular detail. The number'9 represents a base pipe which is imbedded in the central strip 12. Disposed inside the base pipe 9 are a pair of lead wires 8, 8 comprising sources of high voltage electricity for energizing the luminaire. Formed integrally with the base pipe 9 at its upper end is a flange 15, slotted at 16 (Fig. 6) for the reception of a plurality of bolts 17. The bolts 17 extend through openings in'an'upper flange 20 which is formed integrally with a vertical post 21. The. luminaire 13 is aflixed to 'thepost- 21 by' a. split sleeve 22' near the top of the luminaire, and by a'base 23 upon which the luminaire is supported. From Fig. 2 of the drawings it will be apparent that the lead wires 8, 8 extend upwardly into the post 21- and that they extend outwardly through the post 21 and enterthe luminaire 13 through an insulator 28.

Turning nowto' Figs. 3 and 4' of the drawings, it will be apparent that'the base 23' includes a base plate 29 which carries'apairofdependingguardcups 24, 24 comprisingghousings'for. a pair of sockets 25, 25. An inverted U-tube'26 extends vertically upwardly from the sockets 25; 25 and has'aplurality of prongs 27 which are securely engaged within the sockets 25, 25.

Extending upwardly from the base plate 29 is a cylindrical elongated enclosure 30, in which the U.-tube.26 is disposed. A stiflenerplateBl extends transverselyacross the top of the enclosure 30, having an annularv groove in whichithe'upper'ed'ge of enclosure 30' isfitted. Fixed to thetop of plate 3 1 is a dome 32, which includesa removable light' dispersive upper dome portion 33. The

Turning now to Figs. 5 and 7 of the drawings, the reflector plate 14 is fixed to the base plate 29 by means of a plurality of angle irons 41 (Fig. 7). The reflector plate 14 comprises a substantially flat sheet or plate of metal or other material, bent in a single plane forming a plurality of curved reflective surfaces as illustrated in Fig. 5 of the drawings. It will be apparent that the reflector plate 14 shown in Fig. 5 consists of two substantially parabolic portions 42, 43, which intersect one another along the straight line 44. It will be appreciated that the curved portion 42 coacts with the leg 45 of U-tube 26, while the curve portion 43 coacts with the leg 46 of U-tube 26. Each curved portion 42, 43 has a curvature which decreases with increasing distance from the axis of its corresponding U-tube leg, whereby light from the legs is beamed in the same general direction. Each beam has the general form of a rectangular parallelepiped. Preferably the cuwed reflector plates 42, 43, in horizontal section, are segments of parabolas having parallel axes, and the legs 45, 46 are preferably located at the spaced focal points of the parabolas.

Adjustably supported on the base 29, inside the enclosure 30, are a plurality of louvers 47. The louvers 47 have capacity to swing about vertically arranged pivots 48 within the encolsure. It will be observed that the louvers 47 are located adjacent to one edge of the reflector plate 14. The louvers 47 serve to deflect light traveling directly from the vertical leg 45, since they are opaque, and also serve to deflect light reflected from the parabolic portion 43 having the vertical leg 46 as a source. This in an important and advantageous feature of the invention, as will further appear. I

From Fig. 5 it will be apparent that the curved intersecting reflector plates 42, 43 extend substantially completely across the space within the enclosure 30, dividing the enclosure into two sections 50, 51. The section 50 is illuminated and is bounded by the reflective faces of the curved reflector plates. The space 51 is located rearwardly of the curved reflector plates, and is not necessarily illuminated. The wires 8, 8 lead into the rearwardly located enclosure space 51. Mounted in the space 51 is a reactor 52. One wire 8 leads directly to one of the U-tube sockets 25, while the other wire 8 is connected to the end of a coil 53; this wire is also by-passed through a thermostat 54 for connection into an intermediate porhem of the coil 53. The arrangement and wiring of the thermostat and reactor appear in further detail in my aforementioned issued U. S. Patent No. 2,610,289, and constitute no part of this invention.

Turning now to Fig. 8 of the drawings, it will be appreciated that the enclosure for the electric discharge lamp preferably consists of a metal or other opaque body portion 30 having an opening into which a light transmitting window 61 is sealed. Window 61 consists of glass, plastic or the like having good visible light transmission characteristics and a low thermal conductivity when used in cold climates. However, for use in hot climates the window 61 preferably has high thermal conductivity. In the embodiment of the invention illustrated in Figs. 5 and 8, the sealing means between the window and the body portion 30 comprises a continuous rubber or other resilient strip 62, which has opposed slots formed to receive the opposed edges of the members 30, 61. It will be appreciated that it is important to form a good seal between the members 30, 61 since heat developed by the lamp 26, reactor 52, when retained in the enclosure, materially improves the efficiency of operation of the electric discharge lamp in cold weather.

It will also be appreciated from Fig. 8 that two spaced sight members 63, 63 are mounted on the top of the enclosure adjacent to the dome member 32. The sight members are aligned with the principal path of the light beam, and are accordingly located in a fixed position with respect .to the curved reflector plates 42, 43, parallel to the axes of the parabolic reflectors.

While the light beams produced by the apparatus shown in the drawings are preferably substantially parallel to one another, it will be appreciated that the relative arrangement of the lamp and reflectors may be modified in accordance with this invention to provide beams of other types. For example, the reflectors may be hinged together as illustrated at 44a in Figs. 5 and 8 for relative swinging movement about the vertical line 44 along which they intersect, to produce convergent or divergent beams. For this purpose the angle irons 41 shown in Fig. 7 may be provided with slots 70 on their bases and other slots 71 (Fig. 8) may be provided on the reflectors 42, 43. Moreover, utilizing this structure, the reflectors may be moved bodily toward and away from the light sources. Other modifications will be readily apparent and may be made to provide optimum beaming for the particular conditions existing.

In the operation of the electric discharge lamp luminaire, the device is adjusted to the desired angle with respect to the street or highway by loosening the bolts 17 and revolving the luminaire with respect to the flange 15 and post 9. The luminaire may be quickly positioned at any predetermined angle by sighting along the sight members 63, 63. The bolts 17 are then tightened to secure the luminaire in the desired angular position with respect to the street or highway. It will be appreciated that the light beam is substantially restricted to a path extending at an acute angle with respect to the movement of the vehicles on the street or highway, and that the louvers 47, because of their construction and arrangement can .readily be adjusted with respect to the curved reflectors. This greatly reduces or completely eliminates direct glare in adirection substantially parallel to the path of movement of vehicles along the street or highway. Moreover,

the adjustable character of the louvers coacts with the adjustable character of the base. Accordingly, the luminaire is not only a highly efficient source of bright, soft light which is free of glare, but is also constructed to confine the light to a relatively low beam disposed immediately above and parallel to the road surface and extending at an acute angle with respect to the direction of vchicu lar travel thereon.

The construction of the plate 31 and removable dome 33 in combination with the slot 34 in the plate 31 utilizes efficiently the light from the bend of U-tube 26. Moreover, it provides a convenient means for removing and replacing the U-tube 26. This is accomplished by lifting oif the dome 33, reaching through slot 34 to grasp the closed bend of the U-tube, and withdrawing the U-tube through slot 34.

It will be appreciated that the reactor 53 and thermo' stat 54 as shown in the drawings are located at the lowest convenient available space within the enclosure.

This is important. While this arrangement is adequate for service inwarm climates, it is even preferable to locate the reactor wholly below the horizontal plane tangential to the bottom of U-tube 26 when the luminaire is to be used in colder climates. Moreover, for cold weather service the thermostat 54 should be located below the reactor and in the best position for response to the ambient temperature. Furthermore, when the reactor is -mounted below the base plate 29, the base plate 29 should be provided with large openings permitting heated air to How upwardly into the space occupied by the U-tube 26.

While this invention has been described with reference to one specific embodiment-adapted for a specific purpose, it will be appreciated that various changes may be ma de inthe form of the device and in the manner of the spirit and scope of the invention as defined in the appended claims.

Having thus described the invention, I claim:

1. An electric discharge lamp luminaire comprising an enclosure, a U-tube lamp having a bend at the upper end thereof in said enclosure, said enclosure having a brace plate located above the bend of the U-tube, said brace plate being slotted above said bend, and a removable lighting dome located above the slot and supported by said brace plate to receive light from the bend of the U-tube, said light passing through said slot, said dome being removable and said slot being of a size to permit withdrawal of the U-tube through said slot.

2. An electric discharge lamp luminaire comprising an enclosure having a light transmitting window therein, an electric discharge lamp disposed in said enclosure, said lamp including a plurality of generally upright elongated lamp members, a generally upright reflector spaced from said lamp members including a pair of reflective generally parabolic surfaces which intersect each other and which surfaces terminate along the line of intersection, said generally parabolic surfaces having generally parallel axes along which the light is directed and said surfaces having focal points which are spaced from one another measured in the direction of said axes whereby one of said generally parabolic surfaces is arranged forwardly of the other generally parabolic surface measured along the path of the light beam, the remote outer ends of both said parabolic surfaces extending forwardly well beyond a line joining said focal points, said lamp mem bers and the corresponding parabolic surfaces being so arranged that light from either lamp member may impinge directly on either of the extensions of said para bolic surfaces, the intervening space between said extensions being devoid of any light obstruction or barrier, said reflective surfaces being constructed and arranged to reflect the light forming a light beam directed through said window, and a plurality of opaque louvers in said enclosure extending upwardly adjacent to an edge of said window and bounding one edge of said light beam.

3. An electric discharge lamp luminaire comprising an enclosure, a generally upright electric discharge lamp extending substantially from the bottom to the top of said enclosure, said enclosure having brace means located above the upper end of said lamp, said brace means having an opening above said lamp, and a lighting dome located above said opening and supported by said brace means to receive light from the upper portion of said lamp, said light passing through said opening, said dome being removable and said opening being of a size to permit withdrawal of said lamp through said opening.

4. An electric discharge lamp luminaire comprising a substantially upright elongated enclosure, a dome disposed on top of said enclosure, an inverted U-tube electric discharge lamp having legs disposed substantially upright in said enclosure, the closed end of the U being substantially adjacent said dome in position to direct light into said dome, and a reflector spaced below said dome adjacent said U-tube legs, said reflector including a pair of reflective generally parabolic surfaces which intersect each other and which surfaces terminate along the line of intersection, said generally parabolic surfaces having generally parallel axes along which the light is directed and said surfaces having focal points which are spaced from one another measured in the direction of said axes whereby one of said generally parabolic sur faces is arranged forwardly of the other generally parabolic surface measured along the path of the light beam.

5. The luminaire defined in claim 4 wherein a brace plate extends transversely of the upper portion of said enclosure above the U-tube below the dome, and wherein the brace plate has a light-transmitting opening intermediate the U-tube and the dome for permitting light to pass from said U-tube to said dome.

6. An electric discharge lamp luminaire comprising an enclosure having a light transmitting window therein, an electric discharge lamp disposed in said enclosure, said lamp including a plurality of generally upright elongated lamp members, a generally upright reflector spaced from said lamp members including a pair of reflective generally parabolic surfaces which intersect each other and which surfaces terminate along the line of intersection, said generally parabolic surfaces having generally parallel axes along which the light is directed and said surfaces having focal points which are spaced from one another measured in the direction of said axes whereby one of said generally parabolic surfaces is arranged forwardly of the other generally parabolic surface measured along the path of the light beam, the remote outer ends of both said parabolic surfaces extending forwardly well beyond a line joining said focal points, said lamp members and the corresponding parabolic surfaces being so arranged that light from either lamp member may impinge directly on either of the extensions of said parabolic surfaces, the intervening space between said extensions being devoid of any light obstruction or barrier, and said reflective surfaces being constructed and arranged to reflect the light forming a light beam directed through said window.

References Cited in the file of this patent UNITED STATES PATENTS 1,611,127 Bull Dec. 14, 1926 1,627,437 Humphrey May 3, 1927 1,902,860 Kay et al Mar. 28, 1933 2,216,084 Libson Sept. 24, 1940 2,232,499 Waterbury Feb. 18, 1941 2,262,157 Beals Nov. 11, 1941 2,327,820 Rogers Aug. 24, 1943 2,610,289 Brainerd Sept. 9, 1952 2,641,687 Akely June 9, 1953 2,655,591 Clark Oct. 13, 1953 FOREIGN PATENTS 380,033 Great Britain Sept. 8, 1932 451,709 Great Britain Aug. 11, 1936 616,075 Great Britain Jan. 17, 1949 

